WordPress at a glance
function is not described

WP_Widget::save_settings() public WP 2.8.0

Saves the settings for all instances of the widget class.

{} It's a method of the class: WP_Widget{}

No Hooks.

Return

null. Nothing.

Usage

$WP_Widget = new WP_Widget();
$WP_Widget->save_settings( $settings );
$settings(array) (required)
Multi-dimensional array of widget instance settings.

Changelog

Since 2.8.0 Introduced.

Code of WP_Widget::save_settings() WP 5.7.2

<?php
public function save_settings( $settings ) {
	$settings['_multiwidget'] = 1;
	update_option( $this->option_name, $settings );
}